Verification of finite element analysis code CalculiX CrunchiX (ccx) in accordance with ISO 10211:2007

The design standard ISO 10211 provides four thermal problems; a square column, a composite structure, a multi-environment building envelope and an iron bar penetrating an insulation layer. Each test case is described in a standard summary, which includes benchmark target solutions. A numerical code is considered as compliant with the aforementioned standard, providing the solutions for the test cases are within the tolerances for set physical point temperatures and total heat flow. Analyses were conducted using CalculiX suite, an open source code that can build, solve and post-process finite element (FE) models. All FE models were discretized with both first and second order elements and their results compliant with the reference solutions.